Skyline 4-Pot Calipers and Rotors on an A32

[defcon1]

For the past week, I've been sorting out brake problems. My front right brake calipers started clicking...a sure sign that the pistons were jamming. After a proper servicing and cleaning, the clicking persisted, and there was a discernible split second delay in the brakes gripping on the right side, basically causing the car to veer slightly to the left on hard braking. In normal traffic, at normal speeds...no big deal. But on the highway, at highway speeds...:shocked:

A fast tour of the local chop shops nearby revealed that 3.0l dual pot calipers were not too common. Most of the half cut ceffy's coming from Japan were 2.5 litre models, hence sporting the single pot caliper found on the local 2.0 litre versions of the A32.

Now...I have a simple philosophy. IF I have to mod my car for whatever reason, it'd better perform better...so...I grabbed a set of R32 calipers and rotors. The condition was fair at first glance...but on closer inspection, apart from the surface corrosion on the calipers caused by salt on the streets in Japan, and probably being in the rain for about 6 months, it is in pretty good condition. The rotor, once you get past the rust, was only lightly worn.

Well, to cut a long story short...only a slight mod is required to get R32 calipers into an A32. There are 2 problems to solve...

a) It fits into a 16" rim, but...you need a larger offset. That's why people say that you need to change to a set of 17". I solved this problem by bolting on a pair of 1" spacers temporarily. People also tend to say that doing this will cause some imbalance in your front tyres, that you will feel in your steering.

To test this, I took the car to Penang...on the old calipers and rotors, but with the spacers bolted on and went all the way up to 200 kph. There was some wobbling at 120 - 160 kph, but none below and above this range. Also, from the feel of it, it felt more like my tyres needed some balancing rather than the spacers being unbalanced. So, for now, I've passed the spacers for use in this way. These spacers came off a Japan half cut skyline and is probably dynamically balanced on manufacture.

b) If you bolt on the rotors and calipers to A32 knuckle, in the "normal" way, they will go in perfectly. BUT, your calipers will just come in contact with the edge of the R32 rotors. The solution : send the rotors to a machine shop, and machine off about 1mm of it's diameter (not radius). This will give it enough clearance and allow it to bolt on perfectly to the A32 knuckle without any reduction in performance.

Once everything fit...I took it for a spin. Btw...I also put in a set of Bendix brake pads.

Conclusion : Everything works BUT now, I have another little problem. The A32 servo and brake master pump is designed to work with twin pot rotors, and NOT 4-pot. Hence, the servo pump is not strong enough to supply the pressure required by the 4-pot calipers and the master pump may be too small to supply the volume of brake fluid required by the system. The brakes feel soft and spongy, but grips extremely well if you press harder.

Hence, in a couple of days...I have arranged for an A32 servo and master pumps will be installed. This should then be able to supply both the pressure and the volume required by this set of calipers. Plus...the calipers get a new coat of heat resist paint...

I'll post an update, hopefully with some pictures in a few days...

 

[weikee]

if you put the front 1" space, why not put the rear one also. that will balance it up. The R32 minimal can fit to 16", but the R33 onward need 17" already, cause its 310mm.

BTW, what brake hose are you using? cause the twin pot from A32 and R32 have difference bolt type. I think you need to put the 1" master pump, that will be enough.

 

[cmng]

R33 is 295mm
R34 is 310mm

 

[weikee]

yeah, just did a db check.. to be exact is 296mm

and R32 GTS is 280mm = S14 = S15.

 

[edgar_raphael]

when you said:

"...machine off about 1mm of it's diameter.."

did you have a picture of the machined rotor?

I know we can machine the surface, but not that sure about the total diameter of the rotor, or to be specific the size of the rotor.

 

[ongteckweng]

this old man is really maniac when comes to car...
but keep up the good job n post some pics when its done...cheers

 

[weikee]

edgar_raphael,

You can do it in the engineering shop in Malaysia, not sure what you call in Au. Its just like machine the surface, but in 90deg direction.

 

[Ultimate Cefiro]

deffy, i had install the R32 4-pot caliper into my ceffy last time n face the same problem.... the caliper fits but the rotor has to be machined a bit..... but the servo n pump is not strong enuff as stated......then there goes all those squeeking sound when i press the brake.... now oledi dismantle n put back ori..... since u r changing the servo n pump..... wut types u will be installing?? n oso to fit the 2 pot caliper at the rear..... since R32 reardisc is usingthe brake shoes fo e-brake... then how can we modify it since ours is using the pads...??

 

[weikee]

the rear if you need to put in the twin pot, you got to buy another h.brake caliper that drive by the cable, and do a bracket to mount it. Thats how some people do.

Another method its use the rear skyline twin port, with the fatty current single pot, than make a bracket to relocate the single port just for h.brake one. Can be done, just need to send the caliper and link beam to the machine shop to fabricate the mount.

I know one super keng machine shop in Sg Besi... that fellow also repair rims and lots of tires shop bring the rims to the place. Last time i mod my sentra with twin pot VR4, and 4 pot nissan also from the fellow.

 

[Ultimate Cefiro]

ya..... I'm using the R32 rear 2 pot caliper...... so dat means just relocate the h.brake cable will do?? ya eh?? so izzit expensive??

 

[weikee]

you need another caliper to run the h.brake.

if you use the original A32 caliper, should be cheaper.. but at least about 600 to 700 for the labour + material cost.

If you get the external one, Its sold in US maybe more expensive. My friend its install this in his n14, let see how the outcome its.

 

[ongteckweng]

you need another caliper to run the h.brake.

if you use the original A32 caliper, should be cheaper.. but at least about 600 to 700 for the labour + material cost.

If you get the external one, Its sold in US maybe more expensive. My friend its install this in his n14, let see how the outcome its.

wahloa...so expensive?!!!

 

[cmng]

remember..
those caliper you all mention is lug mount.. harder to fabricate
if you using radial mount. .easier to fabricate it

 

[defcon1]

I have a problem. R32 servo will not fit the space. Any ideas?

 

[weikee]

I think you try change the master pump 1st. Cause bigger master pump will delivery more fluid. try get the 1".

You maybe got to also make a custom steel braided hose so you can align with the original hose. Some master pump have difference output of R & F, so get a 2 or 3" steel braided hose, and move the output. Can custom made the hose.

 

[weikee]

some people call master pump as master cylinder.

 

[ongteckweng]

I think you try change the master pump 1st. Cause bigger master pump will delivery more fluid. try get the 1".

You maybe got to also make a custom steel braided hose so you can align with the original hose. Some master pump have difference output of R & F, so get a 2 or 3" steel braided hose, and move the output. Can custom made the hose.

agree...master pump does play a part. i remember putting a pajero pump into my saga turbo last time with twin pot calipers...feels gr8...

but im not sure which master pump will suits a32. r32?

 

[weikee]

for the a32, you need the master pump with hose are on the driver side. cause on the passenger side, the brake hose have no place for it.

Get the 1" piston, cause the s14, and s15 are using it. most silvia have front 4 pot, and rear single pot.. same as the upgraded brake like defcon1. But the s14 / s15 hose are on the passenger side.. thats the problem. I got one s15 master pump with me [:)]


Some very good info on the brake upgrade and master pump info.
http://importnut.net/300zxbrakeswap.htm

 

[weikee]

defcon1,

How is your brake now, any luck with the MC and Servo? Today i went shopping in chop shop, as i found nissan MC have 2 measurement i.e. BMxx and X/Y,

BM44 = 15/16", BM50 = 1", BM55 = 17/16"

What is your MC size now? my fatty is BM44 (15/16"), and my spare s15 MC is BM50 (1"). I was thinking to change my MC to the bigger, when i have a look under the hood, think will be a tough job cause the MC output are to the right (driver side), and my S15 output are to the Left.

Some other info i found today on nissan MV
http://www.nissansilvia.com/forums/index.php?showtopic=222918

 

[defcon1]

Hi Wei Kee,

Swopped in an S14 master pump today. Managed to find one at a local chop shop in USJ...a contact of mine who's in the junk yard business. He's a little pricey, but when you need something different, he is usually able to find it.

It's definitely bigger, about 1" in diameter, and pumps more fluid. There is just enough space for it to go in, and if you are careful, you can bend the metal piping round the pump to fit to the inlets, even if on the other side. No pressure hose required.

I did just a simple job with the piping, but will clean up later. Another thing you have to do is to adjust your pedal clearance or freeplay. This you do from inside the cabin...there's a bolt on the pedal, under the dash. You can't miss it.

The results : The new master pump certainly delivers enough fluids, BUT, I can hardly feel the servo kick in. However, if you pump the pedal twice, there's enough pressure. Conclusion : my servo pump is leaking.

The brakes, however, are gripping well, and after the last couple of days running in, all the noises have subsided.

On Monday, Lee will find me a servo from an A32 or probably an A33. I doubt if any other servo will go in, as there is only milimetres clearances on either side of the servo pump, and in front of the master pump. In order to change the servo, the inlet manifold will have to come off. So, it's not an easy job.

Tuesday, I am off to Malacca for a few days. So, I suppose I will do it when I get back. Meanwhile, my new R32 calipers will have to run off a servo called "my right leg". Fortunately, fatties have heavy right legs...